fio groups all subjobs that set option 'thread' into a single process.
Have them all share a single `struct blkio` instance, with one `struct
blkioq` per thread/subjob. This allows benchmarking multi-queue setups.
Note that `struct blkio` instances cannot be shared across different
processes.
Signed-off-by: Alberto Faria <afaria@xxxxxxxxxx>
---
HOWTO.rst | 8 +-
engines/libblkio.c | 250 +++++++++++++++++++---
examples/libblkio-io_uring.fio | 13 +-
examples/libblkio-virtio-blk-vfio-pci.fio | 13 +-
fio.1 | 7 +-
5 files changed, 257 insertions(+), 34 deletions(-)
diff --git a/HOWTO.rst b/HOWTO.rst
index 763f4f51..4e69abfc 100644
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -2199,7 +2199,13 @@ I/O engine
:option:`libblkio_driver`. If
:option:`mem`/:option:`iomem` is not specified, memory
allocation is delegated to libblkio (and so is
- guaranteed to work with the selected *driver*).
+ guaranteed to work with the selected *driver*). One
+ ``struct blkio`` instance is used per process, so all
+ jobs setting option :option:`thread` will share a single
+ ``struct blkio`` (with one queue per thread) and must
+ specify compatible options. Note that some drivers don't
+ allow several processes to access the same device or
+ file simultaneously, but allow it for threads.
I/O engine specific parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/engines/libblkio.c b/engines/libblkio.c
index a80be66f..987dea4f 100644
--- a/engines/libblkio.c
+++ b/engines/libblkio.c
@@ -249,6 +249,105 @@ static int fio_blkio_set_props_from_str(struct blkio *b, const char *opt_name,
blkio_get_error_msg()); \
})
+static bool possibly_null_strs_equal(const char *a, const char *b)
+{
+ return (!a && !b) || (a && b && strcmp(a, b) == 0);
+}
+
+/*
+ * Returns the total number of subjobs using option 'thread' in the entire
+ * workload that have the given value for the 'hipri' option.
+ */
+static int total_threaded_subjobs(bool hipri)
+{
+ struct thread_data *td;
+ unsigned int i;
+ int count = 0;
+
+ for_each_td(td, i) {
+ const struct fio_blkio_options *options = td->eo;
+ if (td->o.use_thread && (bool)options->hipri == hipri)
+ ++count;
+ }
+
+ return count;
+}
+
+static struct {
+ bool set_up;
+ bool direct;
+ struct fio_blkio_options opts;
+} first_threaded_subjob = { 0 };
+
+static void fio_blkio_log_opt_compat_err(const char *option_name)
+{
+ log_err("fio: jobs using engine libblkio and sharing a process must agree on the %s option\n",
+ option_name);
+}
+
+/*
+ * If td represents a subjob with option 'thread', check if its options are
+ * compatible with those of other threaded subjobs that were already set up.
+ */
+static int fio_blkio_check_opt_compat(struct thread_data *td)
+{
+ const struct fio_blkio_options *options = td->eo, *prev_options;
+
+ if (!td->o.use_thread)
+ return 0; /* subjob doesn't use 'thread' */
+
+ if (!first_threaded_subjob.set_up) {
+ /* first subjob using 'thread', store options for later */
+ first_threaded_subjob.set_up = true;
+ first_threaded_subjob.direct = td->o.odirect;
+ first_threaded_subjob.opts = *options;
+ return 0;
+ }
+
+ /* not first subjob using 'thread', check option compatibility */
+
+ prev_options = &first_threaded_subjob.opts;
+
+ if (td->o.odirect != first_threaded_subjob.direct) {
+ fio_blkio_log_opt_compat_err("direct/buffered");
+ return 1;
+ }
+
+ if (strcmp(options->driver, prev_options->driver) != 0) {
+ fio_blkio_log_opt_compat_err("libblkio_driver");
+ return 1;
+ }
+
+ if (!possibly_null_strs_equal(options->path, prev_options->path)) {
+ fio_blkio_log_opt_compat_err("libblkio_path");
+ return 1;
+ }
+
+ if (!possibly_null_strs_equal(options->pre_connect_props,
+ prev_options->pre_connect_props)) {
+ fio_blkio_log_opt_compat_err("libblkio_pre_connect_props");
+ return 1;
+ }
+
+ if (options->num_entries != prev_options->num_entries) {
+ fio_blkio_log_opt_compat_err("libblkio_num_entries");
+ return 1;
+ }
+
+ if (options->queue_size != prev_options->queue_size) {
+ fio_blkio_log_opt_compat_err("libblkio_queue_size");
+ return 1;
+ }
+
+ if (!possibly_null_strs_equal(options->pre_start_props,
+ prev_options->pre_start_props)) {
+ fio_blkio_log_opt_compat_err("libblkio_pre_start_props");
+ return 1;
+ }
+
+ return 0;
+}
+
static int fio_blkio_create_and_connect(struct thread_data *td,
struct blkio **out_blkio)
{
@@ -329,6 +428,8 @@ err_blkio_destroy:
return 1;
}
+static bool incompatible_threaded_subjob_options = false;
+
static int fio_blkio_setup(struct thread_data *td)
{
/*
@@ -348,6 +449,11 @@ static int fio_blkio_setup(struct thread_data *td)
/* validate options */
+ if (fio_blkio_check_opt_compat(td) != 0) {
+ incompatible_threaded_subjob_options = true;
+ return 1;
+ }
+
if (options->hipri &&
options->wait_mode == FIO_BLKIO_WAIT_MODE_EVENTFD) {
log_err("fio: option hipri is incompatible with option libblkio_wait_mode=eventfd\n");
@@ -380,9 +486,16 @@ out_blkio_destroy:
return ret;
}
+/* per-process state */
+static struct {
+ pthread_mutex_t mutex;
+ int initted_threads;
+ int initted_hipri_threads;
+ struct blkio *b;
+} proc_state = { PTHREAD_MUTEX_INITIALIZER, 0, 0, NULL };
+
/* per-thread state */
struct fio_blkio_data {
- struct blkio *b;
struct blkioq *q;
int completion_fd; /* may be -1 if not FIO_BLKIO_WAIT_MODE_EVENTFD */
@@ -393,12 +506,33 @@ struct fio_blkio_data {
struct blkio_completion *completions;
};
+static void fio_blkio_proc_lock(void) {
+ int ret;
+ ret = pthread_mutex_lock(&proc_state.mutex);
+ assert(ret == 0);
+}
+
+static void fio_blkio_proc_unlock(void) {
+ int ret;
+ ret = pthread_mutex_unlock(&proc_state.mutex);
+ assert(ret == 0);
+}
+
static int fio_blkio_init(struct thread_data *td)
{
const struct fio_blkio_options *options = td->eo;
struct fio_blkio_data *data;
int flags;
+ if (td->o.use_thread && incompatible_threaded_subjob_options) {
+ /*
+ * Different subjobs using option 'thread' specified
+ * incompatible options. We don't know which configuration
+ * should win, so we just fail all such subjobs.
+ */
+ return 1;
+ }
+
/* allocate per-thread data struct */
data = calloc(1, sizeof(*data));
@@ -414,33 +548,54 @@ static int fio_blkio_init(struct thread_data *td)
goto err_free;
}
- /* create, connect, and start blkio */
+ /* initialize per-process blkio */
- if (fio_blkio_create_and_connect(td, &data->b) != 0)
- goto err_free;
+ fio_blkio_proc_lock();
- if (blkio_set_int(data->b, "num-queues", options->hipri ? 0 : 1) != 0) {
- fio_blkio_log_err(blkio_set_int);
- goto err_blkio_destroy;
- }
+ if (proc_state.initted_threads == 0) {
+ int num_queues, num_poll_queues;
- if (blkio_set_int(data->b, "num-poll-queues",
- options->hipri ? 1 : 0) != 0) {
- fio_blkio_log_err(blkio_set_int);
- goto err_blkio_destroy;
- }
+ if (td->o.use_thread) {
+ num_queues = total_threaded_subjobs(false);
+ num_poll_queues = total_threaded_subjobs(true);
+ } else {
+ num_queues = options->hipri ? 0 : 1;
+ num_poll_queues = options->hipri ? 1 : 0;
+ }
- if (blkio_start(data->b) != 0) {
- fio_blkio_log_err(blkio_start);
- goto err_blkio_destroy;
+ /* create, connect, and start blkio */
+
+ if (fio_blkio_create_and_connect(td, &proc_state.b) != 0)
+ goto err_unlock;
+
+ if (blkio_set_int(proc_state.b, "num-queues",
+ num_queues) != 0) {
+ fio_blkio_log_err(blkio_set_int);
+ goto err_blkio_destroy;
+ }
+
+ if (blkio_set_int(proc_state.b, "num-poll-queues",
+ num_poll_queues) != 0) {
+ fio_blkio_log_err(blkio_set_int);
+ goto err_blkio_destroy;
+ }
+
+ if (blkio_start(proc_state.b) != 0) {
+ fio_blkio_log_err(blkio_start);
+ goto err_blkio_destroy;
+ }
}
- /* get queue */
+ /* get per-thread queue */
- if (options->hipri)
- data->q = blkio_get_poll_queue(data->b, 0);
- else
- data->q = blkio_get_queue(data->b, 0);
+ if (options->hipri) {
+ int i = proc_state.initted_hipri_threads;
+ data->q = blkio_get_poll_queue(proc_state.b, i);
+ } else {
+ int i = proc_state.initted_threads -
+ proc_state.initted_hipri_threads;
+ data->q = blkio_get_queue(proc_state.b, i);
+ }
/* enable completion fd and make it blocking */
@@ -468,13 +623,25 @@ static int fio_blkio_init(struct thread_data *td)
data->completion_fd = -1;
}
+ ++proc_state.initted_threads;
+
+ if (options->hipri)
+ ++proc_state.initted_hipri_threads;
+
/* Set data only here so cleanup() does nothing if init() fails. */
td->io_ops_data = data;
+ fio_blkio_proc_unlock();
+
return 0;
err_blkio_destroy:
- blkio_destroy(&data->b);
+ if (proc_state.initted_threads == 0)
+ blkio_destroy(&proc_state.b);
+err_unlock:
+ if (proc_state.initted_threads == 0)
+ proc_state.b = NULL;
+ fio_blkio_proc_unlock();
err_free:
free(data->completions);
free(data->iovecs);
@@ -514,7 +681,7 @@ static int fio_blkio_post_init(struct thread_data *td)
.fd = -1,
};
- if (blkio_map_mem_region(data->b, ®ion) != 0) {
+ if (blkio_map_mem_region(proc_state.b, ®ion) != 0) {
fio_blkio_log_err(blkio_map_mem_region);
return 1;
}
@@ -527,11 +694,27 @@ static void fio_blkio_cleanup(struct thread_data *td)
{
struct fio_blkio_data *data = td->io_ops_data;
+ /*
+ * Subjobs from different jobs can be terminated at different times, so
+ * this callback may be invoked for one subjob while another is still
+ * doing I/O. Those subjobs may share the process, so we must wait until
+ * the last subjob in the process wants to clean up to actually destroy
+ * the blkio.
+ */
+
if (data) {
- blkio_destroy(&data->b);
free(data->completions);
free(data->iovecs);
free(data);
+
+ fio_blkio_proc_lock();
+
+ if (--proc_state.initted_threads == 0) {
+ blkio_destroy(&proc_state.b);
+ proc_state.b = NULL;
+ }
+
+ fio_blkio_proc_unlock();
}
}
@@ -546,7 +729,7 @@ static int fio_blkio_iomem_alloc(struct thread_data *td, size_t size)
/* round up size to satisfy mem-region-alignment */
- if (blkio_get_uint64(data->b, "mem-region-alignment",
+ if (blkio_get_uint64(proc_state.b, "mem-region-alignment",
&mem_region_alignment) != 0) {
fio_blkio_log_err(blkio_get_uint64);
return 1;
@@ -556,14 +739,16 @@ static int fio_blkio_iomem_alloc(struct thread_data *td, size_t size)
/* allocate memory region */
- if (blkio_alloc_mem_region(data->b, &data->mem_region,
+ fio_blkio_proc_lock();
+
+ if (blkio_alloc_mem_region(proc_state.b, &data->mem_region,
aligned_size) != 0) {
fio_blkio_log_err(blkio_alloc_mem_region);
ret = 1;
goto out;
}
- if (blkio_map_mem_region(data->b, &data->mem_region) != 0) {
+ if (blkio_map_mem_region(proc_state.b, &data->mem_region) != 0) {
fio_blkio_log_err(blkio_map_mem_region);
ret = 1;
goto out_free;
@@ -576,8 +761,9 @@ static int fio_blkio_iomem_alloc(struct thread_data *td, size_t size)
goto out;
out_free:
- blkio_free_mem_region(data->b, &data->mem_region);
+ blkio_free_mem_region(proc_state.b, &data->mem_region);
out:
+ fio_blkio_proc_unlock();
return ret;
}
@@ -586,8 +772,12 @@ static void fio_blkio_iomem_free(struct thread_data *td)
struct fio_blkio_data *data = td->io_ops_data;
if (data && data->has_mem_region) {
- blkio_unmap_mem_region(data->b, &data->mem_region);
- blkio_free_mem_region(data->b, &data->mem_region);
+ fio_blkio_proc_lock();
+
+ blkio_unmap_mem_region(proc_state.b, &data->mem_region);
+ blkio_free_mem_region(proc_state.b, &data->mem_region);
+
+ fio_blkio_proc_unlock();
data->has_mem_region = false;
}
diff --git a/examples/libblkio-io_uring.fio b/examples/libblkio-io_uring.fio
index e5885094..99a79dbe 100644
--- a/examples/libblkio-io_uring.fio
+++ b/examples/libblkio-io_uring.fio
@@ -3,6 +3,10 @@
; Replace "libblkio_path" below with the path to your file or device, or
; override it by passing the '--libblkio_path=...' flag to fio.
;
+; In the example below, the two subjobs of "job-B" *and* the single subjob of
+; "job-C" will share a single `struct blkio` instance, and "job-A" will use a
+; separate `struct blkio` instance.
+;
; For information on libblkio, see: https://gitlab.com/libblkio/libblkio
[global]
@@ -15,4 +19,11 @@ direct=1
time_based=1
runtime=10s
-[job]
+[job-A]
+
+[job-B]
+numjobs=2 ; run two copies of this job simultaneously
+thread=1 ; have each copy run as a separate thread in the *same* process
+
+[job-C]
+thread=1 ; have the job run as a thread in the *same* process as "job-B"
diff --git a/examples/libblkio-virtio-blk-vfio-pci.fio b/examples/libblkio-virtio-blk-vfio-pci.fio
index ba89f7ef..f78e5714 100644
--- a/examples/libblkio-virtio-blk-vfio-pci.fio
+++ b/examples/libblkio-virtio-blk-vfio-pci.fio
@@ -3,6 +3,10 @@
; Replace "libblkio_path" below with the path to your device's sysfs directory,
; or override it by passing the '--libblkio_path=...' flag to fio.
;
+; In the example below, the two subjobs of "job-B" *and* the single subjob of
+; "job-C" will share a single `struct blkio` instance, and "job-A" will use a
+; separate `struct blkio` instance.
+;
; For information on libblkio, see: https://gitlab.com/libblkio/libblkio
[global]
@@ -14,4 +18,11 @@ blocksize=4k
time_based=1
runtime=10s
-[job]
+[job-A]
+
+[job-B]
+numjobs=2 ; run two copies of this job simultaneously
+thread=1 ; have each copy run as a separate thread in the *same* process
+
+[job-C]
+thread=1 ; have the job run as a thread in the *same* process as "job-B"
diff --git a/fio.1 b/fio.1
index f20a4164..cc743174 100644
--- a/fio.1
+++ b/fio.1
@@ -1994,7 +1994,12 @@ engine specific options. (See \fIhttps://xnvme.io/\fR).
Use the libblkio library (\fIhttps://gitlab.com/libblkio/libblkio\fR). The
specific \fBdriver\fR to use must be set using \fBlibblkio_driver\fR. If
\fBmem\fR/\fBiomem\fR is not specified, memory allocation is delegated to
-libblkio (and so is guaranteed to work with the selected \fBdriver\fR).
+libblkio (and so is guaranteed to work with the selected \fBdriver\fR). One
+\fBstruct blkio\fR instance is used per process, so all jobs setting option
+\fBthread\fR will share a single \fBstruct blkio\fR (with one queue per thread)
+and must specify compatible options. Note that some drivers don't allow several
+processes to access the same device or file simultaneously, but allow it for
+threads.
.SS "I/O engine specific parameters"
In addition, there are some parameters which are only valid when a specific
\fBioengine\fR is in use. These are used identically to normal parameters,
--
2.38.1
